Armor-plating composite

ABSTRACT

A composite material for armor plating with improved multihit behavior includes at least: a front layer, facing the impact side and mounted on a first sub-layer, the front layer including a plurality of neighboring front-layer segments with form-fit contact between adjacent segments; a rear layer facing away from the impact side; and a supporting layer disposed between the front and rear layers. The supporting layer includes a plurality of supporting-layer segments, which present a surface parallel to the front layer whose area is the same as or less than the area of the front-layer segments parallel to the front layer.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a composite armor-plating material comprisingat least: a front layer, facing the impact side and mounted on a firstsub-layer, the front layer consisting of a plurality of neighboringfront-layer segments with form-fit contact between adjacent segments; arear layer facing away from the impact side; and a supporting layerdisposed between the front layer and the rear layer.

2. Discussion of Related Art

Composite armor-plating materials of this type are used for protectionagainst projectiles and the use of explosives, e.g., in armor-platedvehicles, or for the protection of persons and/or objects in railwaystations, airports or public buildings.

Thus DE-A-39 37 087 discloses an armor-plated component in which thearmor plate is mounted on a lightweight supporting element and providedwith a covering layer on is its front side. The armor plate consists ofa ceramic composite with a sub-layer of aramid or glass-reinforcedplastic on the rear face. The supporting element can be of a lightweightmaterial such as aluminum, wood or similar, or it can be produced from amaterial incorporating cavities, such as perforated plates or rigidfoam. Armor plating of this type is claimed to provide effectiveprotection.

WO 96/29561 discloses a multilayered armor-plating material that isconstructed from an optionally monolithic or multicomponent ceramic ormetallic front layer backed by a hard supporting layer. In this patent,synthetic resin laminated wood is used as the supporting layer.Furthermore, the synthetic resin laminated wood layer may carry anadditional layer on the side facing away from the front armor-plating;this additional layer may be made of, in particular, armor-platingsteel, a duralumin material, a titanium alloy, a GRP or an aramidlaminate. This structure is claimed to provide a multilayerarmor-plating material that is lightweight, rigid and reasonably priced.It is for all practical purposes not delaminated, even in the impactregion, when subjected to high stress, and is moreover capable ofdissipating energy.

When testing the penetration resistance properties of material inaccordance with DIN EN 1522, a dispersion pattern in the form of anequilateral triangle is imposed as an additional condition in order toinvestigate the multihit behavior of the armor plating. According to thecurrently valid regulations, the side length of the triangle must be120±10 mm.

According to WO 96/29561, the multihit capability of the compositearmor-plating material disclosed therein is superior to that of astructure in which a GRP layer is used instead of the synthetic resinlaminated wood layer. It has been suggested in WO 96/29561 that thepermissible dispersion is roughly half of that in an optimizedceramic/GRP and/or aramid composite of the usual construction. However,WO 96/29561 contains no test results, so that no conclusions can bedrawn on the actually attainable multihit behavior of the structuredisclosed therein.

U.S. Pat. No. 4,241,457 discloses a protective garment comprisingsegmented plates. The plates of the first and second layers have thesame dimensions but are staggered with respect to one other.

U.S. Pat. No. 2,723,214 discloses a material suitable for use inprotective clothing that has three segmented layers of plates, eachmounted on a layer of elastic material. The segments of the plate facingthe impact side have a smaller surface area than the segments of theunderlying plates, and are so arranged that the junctions at their edgesor joints do not fall directly above and parallel to any of the jointsin the directly neighboring layer.

Requirements placed on the protection to be provided by armor platingare becoming increasingly stringent, and it is entirely possible that,for a dispersion pattern in the form of an equilateral triangle, shorterside lengths will be required in future. In fact side lengths as low as45 mm have recently been discussed.

SUMMARY OF THE INVENTION

The object of the present invention, therefore, is to provide acomposite armor-plating material showing improved multihit behavior thatalso meets requirements for a dispersion pattern with reduceddispersion.

This object is achieved with a composite armor-plating materialcomprising at least: a front layer, facing the impact side and mountedon a first sub-layer, the front layer consisting of a plurality ofneighboring front-layer segments with form fit contact between adjacentsegments; a rear layer facing away from the impact side; and asupporting layer, disposed between the front layer and the rear layerand consisting of a plurality of supporting-layer segments, wherein thesupporting-layer segments present a surface, parallel to the frontlayer, whose area is the same as or less than the area of thefront-layer segments parallel to the front layer, and wherein thesupporting-layer segments are arranged underneath the front-layersegments in such a way that their edges are exactly superposed.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagrammatic representation of the cross-section of acomposite armor-plating material of the invention.

FIG. 2 is a top view of the front layer.

FIG. 3 is a diagrainatic representation of the cross-section of acomposite armor-plating material of the invention that includes acovering layer and a honeycomb structure.

DESCRIPTION OF PREFERRED EMBODIMENTS

It is possible in this case to place under each front-layer segment asupporting-layer segment of the same area as the front-layer segment sothat their edges are exactly superposed. Alternatively, a group of twoor more supporting-layer segments can also be placed under a front-layersegment, the group having the same total area as the front-layersegment, and the edges of the group as a whole and those of thefront-layer segment being exactly superposed.

The first sub-layer for the front-layer segments can consist of afiber-reinforced plastic of low thickness, such as an aramid laminate, aglass-fiber reinforced plastic, or a polyethylene laminate. Thepreferred material is an arachnid laminate consisting of, for example,two or three layers of woven aramid yarn embedded in an elastomermatrix.

A single laminated woven layer may also be used. The front-layersegments may be affixed to the sub-layer with an adhesive, such as apolyurethane-based adhesive. The supporting-layer segments may also bemounted on a sub-layer. This could consist of, for example,fiber-reinforced plastic, plastic sheeting or a glass fabric, whichcould advantageously be provided with self-adhesive on one side so thatthe supporting-layer segments can be affixed to it directly. It is alsopossible, however, to dispense with a separate sub-layer for thesupporting-layer segments, and to affix these directly to the rear layerwith, e.g., an adhesive. The material for the rear layer, also known asthe backing, may be a fibrous composite, in particular an aramidlaminate. This consists of a plurality of layers of woven aramid yarnthat are coated on one or both sides with an elastomeric material, aresin such as phenolic resin, or a thermoplastic material, and thenlaminated together.

The front-layer segments may be provided with a covering layer (20 inFIG. 3) on the side facing the direction of impact; this may take theform of a coating of aluminum, glass or aramid fabric laminated onto thefront layer.

The first sub-layer with the front-layer segments, which may be providedwith a covering layer, can be affixed with adhesive to thesupporting-layer segments mounted on the second sub-layer; the secondsub-layer can be similarly affixed with adhesive to the rear layer.

The front-layer segments are preferably ceramic tiles. In the case ofsquare tiles, their dimensions should lie between 20 mm×20 mm and 100mm×100 mm, preferably between 20 mm×20 mm and 50 mm×50 mm. Triangular,hexagonal or rectangular tiles may also be used. If square tiles areused of which the cross-sectional area for the side facing the directionof impact is, e.g., 30 mm×30 mm, the supporting-layer segments are,according to the invention, also square and of dimensions 30 mm×30 mm.However, they may also have a smaller area than the tiles so that, forexample, two segments of the supporting layer, each having across-sectional area of 15 mm×30 mm, may be fitted under a tile of size30 mm×30 mm. It is also possible to fit more than two supporting-layersegments under a single tile, e.g., three segments, each of size 10mm×30 mm, under a tile of size 30 mm×30 mm. If the tiles constitutingthe front layer, and the supporting-layer segments, are of equal size, aparticularly advantageous embodiment of the invention is one in whicheach segment of the supporting layer is positioned directly under a tilesuch that the edges of the supporting-layer segment and those of thetile are exactly superposed. Each tile is therefore associated withexactly one supporting-layer segment, which has no direct contact withother tiles.

If supporting-layer segments are used that are smaller than the tiles,their dimensions should be chosen such that the total area of thesupporting-layer segments that are combined into a group corresponds tothe area of one tile, and that the group of supporting-layer segmentscan be so arranged under a tile that the edges of the group and those ofthe tiles are exactly superposed. In this way, every tile is associatedwith a group of supporting-layer segments that has no direct contactwith other tiles.

It has been shown that in multiple bombardment of conventional armorplating consisting of a layer of ceramic tiles mounted on a backing, thesecond or third shot is not withstood when the dispersion is small, evenif the individual shots do not impact the same ceramic tile. This is dueto the fact that the backing bulges after the very first shot, so thatneighboring ceramic tiles no longer have the necessary stability orsupport from the backing to withstand a further shot. As stated above,it has been suggested in the prior art that a reinforcing layer beplaced under the front layer to serve as a supporting layer. It has beenshown, however, that even this is insufficient to withstand a shot witha dispersion pattern in the form of an equilateral triangle with a sidelength of less than around 50 mm, for example. This problem issurprisingly solved by the object of the invention.

If the front-layer segments are not ceramic tiles but segments ofextremely hard steels, the problem of unsatisfactory multihit behaviorbecomes less important, because structures of this type are better atwithstanding multiple bombardment as compared with ceramic-tilestructures. However, structures in which a steel is used as thefront-layer material have the disadvantage of being appreciably heavierthan ceramic structures. In this respect, also, the invention offers anadvantage. Owing to the segmented supporting layer of the invention thatis positioned between the front layer and the backing, the thickness ofthe steel segments forming the front layer can be reduced without anydeterioration in multihit behavior, and with the added advantage of areduction in weight.

For the purposes of the invention, the supporting-layer segments shouldconsist of a rigid, lightweight material. A particularly suitablematerial is one consisting of thin upper (6 a in FIG. 3) and lower (6 bin FIG. 3) plates connected to each other by bridging elements in ahoneycomb structure (6 c in FIG. 3). These materials, also used inaircraft construction, are distinguished by light weight combined withhigh rigidity. Honeycomb structures of this type usually consist of suchmaterials as aluminum, paper or plastics reinforced with aramid orcarbon fibers or glass fibers. In addition to materials with honeycombstructure, a solid material, such as a solid plastic plate of, e.g.,polycarbonate or a wooden plate, may also be used for thesupporting-layer segments. The thickness of the supporting-layersegments should be between 2 mm and 10 mm.

In what follows, the invention will be described in more detail with thehelp of figures and examples.

In FIG. 1, the number 10 indicates a composite armor-plating material ofthe invention. This consists of a front layer 2 that faces the directionof impact (denoted here by the arrow 1) and that is made up of aplurality of front-layer segments 3, neighboring segments abutting oneother. The front-layer segments 3 are mounted on a first sub-layer 4.The number 5 represents a supporting layer that, according to theinvention, comprises supporting-layer segments 6. The supporting-layersegments 6 are mounted on a second sub-layer 7. Following the secondsub-layer 7 is the rear layer or backing 8, which faces away from theimpact side 1.

FIG. 2 is a top view of the front layer 2 in the direction of the arrow1 of FIG. 1. The front layer 2 is constructed from, e.g., nine squarefront-layer segments 3. The first sub-layer 4 for the front-layersegments 3 is not shown in the figure in order to show how thesupporting-layer segments 6′ and 6″ can for example be arranged relativeto the front-layer segments 3. The area of the supporting-layer segments6′ and 6″ is in every case half that of a front-layer segment 3. Twosupporting-layer segments 6′ are arranged under a front-layer segment 3and two supporting-layer segments 6″ under the neighboring front-layersegment, in an alternating pattern. The supporting-layer segments 6′ and6″ are at an angle of 90° to each other. The two supporting-layersegments 6′ form a group and are so arranged under a front-layer segment3 that the group and the front-layer segment 3 are exactly superposed.The same applies for the two supporting-layer segments 6″.

EXAMPLE 1

The penetration-resistance properties of a composite armor platingmaterial of the invention were tested in accordance with DIN EN 1522.The composite material consisted of an 8.5 mm thick ceramic structure oftiles of dimensions 30 mm×30 mm, on a first sub-layer comprising atwo-layer aramid laminate of TWARON® T750 woven fabric, and a 5 mm thickhoneycomb structure which was in the form of 30 mm×30 mm segments. Thesesupporting-layer segments were affixed to a layer of self-adhesive glassfabric serving as a sub-layer. The backing consisted of an 18-layeraramid laminate (TWARON® T750 laminate, rubberized). The thickness ofthe composite material was 24.5 mm and the mass per unit area was 471.9g/dm².

The test was carried out under the following conditions.

Caliber: 7.62 mm × 51 Bullet type: VMS/HK (FNB) (full metal jacketspitzer bullet with hard core) Bullet mass: 9.75 g Weapon: Messlauf,twist length 254 mm Barrel length: 658 mm Range: 10.00 m AdditionalDispersion 1/2 = 40 mm conditions: Dispersion 1/3 = 40 mm Dispersion 2/3= 35 mm

No. Velocity V (7.50) Energy E (7.50) Penetration 1 824 m/s 3310 J no 2828 m/s 3342 J no 3 825 m/s 3318 J no

The above data confirm that even at very low dispersion where No. 1 andNo. 3 moreover entered at a seam, such hits being particularly difficultto stop, the composite armor-plating material of the invention possessesoutstanding properties and meets the requirements of resistance classFB7-NS as specified in DIN EN 1522.

EXAMPLE 2

The penetration-resistance properties of a second compositearmor-plating material of the invention were tested in accordance withDIN EN 1522. The composite material consisted of a 9 mm thick ceramicstructure of 25 mm×25 mm tiles, mounted on a first sub-layer comprisinga two-layer aramid laminate, and a 5 mm thick honeycomb material ofCorlight in the form of 25 mm×25 mm segments. The honeycomb materialconsisted of an upper and a lower plate of glass fabric, between whichpaper honeycombs were arranged. These supporting-layer segments wereaffixed to a layer of self-adhesive glass fabric serving as a sub-layer.The backing consisted of an 18-layer aramid laminate. The tiles wereprovided with a layer of glass-fiber woven fabric on the impact side.The thickness of the composite material was 25 mm and the mass per unitarea was 501.2 g/dm².

The test was carried out under the following conditions.

Caliber: 7.62 mm × 51 Bullet type: HK FNB (full metal jacket spitzerbullet with hard core) Bullet mass: 9.75 g Weapon: Messlauf, twistlength 254 mm Barrel length: 658 mm Range: 10.00 m Additional Dispersion1/2 = 35 mm conditions: Dispersion 1/3 = 35 mm Dispersion 2/3 = 32 mm

No. Velocity V (7.50) Energy E (7.50) Penetration 1 817 m/s 3254 J no 2820 m/s 3278 J no 3 821 m/s 3286 J no

Despite the extremely low dispersion, the composite armor-platingmaterial of the invention in Example 2 also shows outstanding propertiesand meets the requirements of resistance class FB7-NS as specified inDIN EN 1522.

COMPARISON EXAMPLE

The penetration-resistance properties of a composite armor-platingmaterial were tested in accordance with DIN EN 1522. The compositematerial consisted of an 8.5 mm thick ceramic structure of 30 mm×30 mmtiles, on a first sub-layer consisting of a two-layer aramid laminate,and a 5 mm thick honeycomb that was not segmented. The backing consistedof an 18-layer aramid laminate. The tiles were provided with a layer ofglass-fiber/epoxy on the impact side. The thickness of the composite was24.4 mm and the mass per unit area was 463.4 g/dm².

The test was carried out under the following conditions.

Caliber: 7.62 mm × 51 Bullet type: VMS/HK (FNB) (full metal jacketspitzer bullet with hard core) Bullet mass: 9.75 g Weapon: Messlauf,twist length 254 mm Barrel length: 650 mm Range: 10.00 m AdditionalDispersion 1/2 = 40 mm conditions: Dispersion 1/3 = 40 mm Dispersion 2/3= 40 mm

No. Velocity V (7.50) Energy E (7.50) Penetration 1 855 m/s 3310 J no 2828 m/s 3342 J yes 3 818 m/s 3262 J no

The armor-plating material of the comparison example did not showpenetration for a dispersion pattern in the form of an equilateraltriangle of side length 120 mm. Nevertheless, the above data show that acomposite armor-plating material with a protective layer that is,however, not segmented, shows unsatisfactory penetration-resistanceproperties at low dispersion and therefore does not possess the requiredfavorable multihit properties.

What is claimed is:
 1. Composite armor-plating material comprising atleast: a front layer, facing an impact side and mounted on a firstsub-layer, the front layer comprising a plurality of neighboringfront-layer segments with form-fit contact between adjacent segments; arear layer facing away from the impact side; and a supporting layerdisposed between the front layer and the rear layer and comprising aplurality of supporting-layer segments, where each of thesupporting-layer segments present a surface parallel to the front layer,which surface has a surface area that is the same as or less than asurface area of a surface of each of the front-layer segments parallelto the front layer, where the supporting-layer segments are so arrangedunderneath the front-layer segments that edges of the supporting-layersegments and edges of the front-layer segments are exactly superposed,and wherein the first sub-layer bearing the front-layer segments isaffixed with adhesive to the supporting-layer segments, which supportinglayer segments are mounted on a second sub-layer, and wherein the secondsub-layer is affixed with adhesive to the rear layer.
 2. Compositearmor-plating material according to claim 1, wherein one of theplurality of supporting-layer segments arranged under each front-layersegment and has a surface having a same surface area as a surface of thefront-layer segment.
 3. Composite armor-plating material according toclaim 1, wherein a group of two or more of the plurality ofsupporting-layer segments are placed under one of the plurality of frontlayer segments, the group having a same total surface area as a surfaceof the front-layer segment, and edges of the group and edges of thefront-layer segment are exactly superposed.
 4. Composite armor-platingmaterial according to claim 1, wherein the first sub-layer for thefront-layer segments comprises a fiber-reinforced material.
 5. Compositearmor-plating material according to claim 4, wherein the first sub-layercomprises an aramid laminate, a glass-fiber reinforced plastic or apolyethylene laminate.
 6. Composite armor-plating material according toclaim 1, wherein the supporting-layer segments are mounted on the secondsub-layer.
 7. Composite armor-plating material according to claim 6,wherein the second sub-layer for the supporting-layer segments comprisesa fiber-reinforced plastic, plastic sheeting or a glass fabric. 8.Composite armor-plating material according to claim 1, wherein thefront-layer segments are ceramic tiles or small steel plates. 9.Composite armor-plating material according to claim 1, wherein thefront-layer segments and the supporting-layer segments are square,rectangular, triangular or hexagonal in shape.
 10. Compositearmor-plating material according to claim 1, wherein thesupporting-layer segments are made of a rigid material.
 11. Compositearmor-plating material according to claim 1, wherein thesupporting-layer segments comprise a honeycomb structure disposedbetween an upper and a lower thin plate.
 12. Composite armor-platingmaterial according to claim 1, wherein the rear layer comprises afibrous composite.
 13. Composite armor-plating material according toclaim 1, wherein the rear layer comprises an aramid laminate. 14.Composite armor-plating material according to claim 1, wherein thefront-layer segments are affixed with adhesive to the first sub-layerand wherein the supporting-layer segments are affixed with adhesive tothe second sub-layer.
 15. Composite armor-plating material according toclaim 1, wherein the front-layer segments are provided with a coveringlayer on the impact side.